1. Field of the Invention
This invention relates to a restorative neuropharmacological agent for motor and speech disturbance originating from central nervous system disorders.
2. Description of Related Art
L-threo-DOPS (Droxidopa) is a central norepinephrine precursor and is known as an active ingredient for norepinephrine activated nerve function improving agents. Clinically, L-threo-DOPS is used to improve impotent feet and orthostatic dizziness in Parkinson's disease (stage 3 in the degree of severity according to Yahr) and also to improve orthostatic hypotension, syncope and orthostatic dizziness in familial amyloid polyneuropathy or Shy-Drager Syndrome.
Conventionally, improvement of motor and speech disturbance originating from central nervous system disorders has been difficult to treat, and the development of a therapeutic agent was generally believed to be impossible.